Instead of the acceptor thread doing it when reusing the session, have
the worker threads clean it out before putting it on the free list.

It could be, and probably was, argued that this is a performance
pessimization, but having thought much about it, I can't spot the
argument any longer, and certainly moving load off the acceptor thread
to the massively parallel worker threads is a good idea.



git-svn-id: http://www.varnish-cache.org/svn/branches/2.0@4281 d4fa192b-c00b-0410-8231-f00ffab90ce4